<ORIGINAL>Microradiography in the differentiation and definite diagnosis of odontomas

The present study evaluated the usefulness of microradiography in differentiny and making a definite diagnosis of odontomas. A surgically removed odontoma from a 14-year-old girl was used here. The specimen was sectioned at approximately 100μm thickness and ground to 50μm. Microradiographic images were obtained using soft X-ray equipment (Sofron, Japan) under the conditions of : tube voltage, 10kVp ; tube current, 5mA ; FSD 7.5cm ; and exposure time, 20min. The images were evaluated by comparing to images obtained by histological procedures. The results showed that the microradiographic images had almost the same resolution as that of the microscopic images

Chemokine Receptor Expression in Oral Squamous Cell Carcinoma Correlation with Growth Factor- and Cytokine-mediated Cell Migration in vitro

AbstractMetastasis is the chief cause of mortality in cancer patients. Recently, chemokines and chemokine receptors were shown to play an important role in the metastasis of various cancers. We examined the role of chemokine receptor-mediated signaling in the invasion potential of human oral squamous cell carcinoma (OSCC) cell lines that were derived from 5 primary tumors and 6 cervical lymph node metastases. Comprehensive analysis of the mRNAs for human chemokine receptors showed that the OSCC cell lines had uniform expression patterns of chemokine receptors. Overall, there were no consistent differences in the expression of chemokine receptors between primary site- and lymph node metastasis-derived cell lines. However, a highly invasive OSCC cell line (SAS-H1) expressed up-regulation of CCR5, CCR6, CCR7, CXCR1, CXCR6 and CX3CR1 compared to a poorly invasive OSCC cell line (SAS-L1). Then we examined whether factors in the tumor microenvironment regulated chemokine receptor expression in SAS-H1 cells. Specifically, transforming growth factor (TGF) -β1 enhanced the expression of CCR5, CCR6, CCR7 and CX3CR1. Pretreatment of SAS-H1 cells with transforming growth factor (TGF) -β1 increased the expression of CCR7 and CX3CR1, and then enhanced CCL21- and CX3CL1-induced directional migration (1.5-fold enhancement as compared with untreated control). In addition, CX3CL1 increased the adhesion of SAS-H1 cells on uncoated tissue culture plates. Neither chemokine stimulated cell proliferation. Treatment of SAS-H1 cells with CX3CL1 activated the phosphotidylinositol-3-kinase (PI3K) and MEK signal transduction pathways. Our results suggest that chemokine receptor-mediated signaling is involved in the local invasion and metastasis of human OSCC

<ORIGINAL ARTICLE>Histologic investigation of tissue surrounding bone in a HA-coated implant supported super structure with and without stress-absorbing elements

The effectiveness of the implant-supported overdentures has been attracted attention for edentulous patients, and a number of studies have been reported. Implant-supported overdentures refer to implant-retained tissue-borne overdentures and it is different from the implant-supported fixed partial dentures recommended by Branemark. In implant-supported overdentures, the functional load may concentrate on implant where there is rigid connection. Loaded implants may cause a resorption of surrounding bone, leading to malfunction, loosing, and the ultimate failure of the implant. The present study reports a stress-absorbing element using a resilient compound designed as the super structure of a two-piece titanium core with hydroxyapatite coated cylinder implants, to avoid stress concentrations, and a histological comparison of the surrounding bone tissue with rigid elements. No notable histological differences were observed in the trabecular patterns by contact microradiography and light microscopy

<ORIGINAL REPORT>X-ray scanning analytical microscopic and scanning electron microscopic studies of an unusual case of dens invaginatus

A mass was extirpated from the region of the maxillary right third molar of a 20 year-old patient. It was proved to be an extreme and unerupted case of dens invaginatus. The clinical and histopathological features have been presented in a previous paper. Ameloblasts and odontoblasts were noted along the surface of enamel or dentin. In the present study, X-ray scanning analytical microscopy (XSAM), a newly developed technique, together with scanning electron microscopy (SEM) was applied for the study of this malformed tooth. SEM study showed a strange arrangement of well-formed enamel and dentin in normal structures. The distribution of calcium (Ca) and phosphorus (P) was clearly observed by the XSAM method. It revealed that the bulk of dentin was composed of two kinds of dentin quite different in mineral content while their SEM appearances were similar. The part of the dentin near the dentinoenamel junction had much higher Ca and P concentrations than the outer parts. In conclusion, the disagreement between the microscopic findings and the XSAM findings suggests the importance of applying various methods in studies to obtain a comprehensive understanding of such malformation. In addition, the present investigation also points out the complexity of the disturbance ranging within the term dens invaginatus

Complications of mandibular sagittal split osteotomy for correction of mandibular prognathism

Sagittal split ramus osteotomy is most frequently performed to correct mandibular prognathism. In this study, intra- and postoperative complications were evaluated in 92 patients treated with this technique. Intraoperative complications occurred in 6 cases (6.5%) of the cases. In addition to experience and skill, complications appeared related to the design of the osteotomy and to attention to detail during the operation. Neurological damage following the sagittal split ramus osteotomy is a common complication after the surgery. Here, sensory disturbance was observed in 63 cases (68.5%) several days after the operation, and in 21 cases (22.8%) at 6 months, 8 cases (8.7%) at one year, 5 cases (5.4%) at 2 years, and 3 cases (3.3%) at 3 years. It was suggested that nerve damage is closely related to the degree of strain and compression of the inferior alveolar nerve

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Fungal infections of the paranasal sinuses is considered rare. This report describes a case of aspergillosis of the maxillary sinus. The patient was a 65-year-old male who underwent the extraction of a maxirally molar tooth under odontogenic maxirally sinusitis. After the extraction, swelling and pain of the right cheek and pus discharge continued through the extraction wound. The patient was referred to the hospital, and X-ray examination showed opacification of the right maxirally sinus. The clinical diagnosis was right odontogenic maxirally sinusitis, and radical maxillary sinus operation and counter opening was performed conventionally. Histopathological examination of surgical specimens revealed aspergillus. Follow up to 10months after the operation showed no recurrence

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It is well known that hydroxyapatite (HAP), which has a high tissue affinity and superior bone conductivity, shows different characteristics depending on the sintering temperature. This study prepared single hydroxyapatite (SHAP) and coated hydroxyapatite (CHAP). The SHAP was sintered at high temperature (1250℃). The structure of CHAP was low temperature (150℃) sintered apatite coated with SHAP. The usefulness of CHAP for bone formation was examined in cylindrical bone defects (diameter : 5mm ; depth : 9mm) created in the mandible of adult dogs 2 months after extraction of the teeth (P4, M1). Calcein (8mg/kg) was injected 2 days before scarification and mandibular bone was removed at 7, 14, 30, 60, 90, and 120days. The explanted bone was fixed in 10% formaldehyde in saline and soaked in Villanueva bone stain solution. Non-demineralized coronal sections (70μm) were made and observed by fluorescence microscopy and microradiography. At 7days after implantation, bone formation occurred from the cavity surface in the CHAP group, but not in the SHAP group. At 14days, newly formed bone was observed around the HAP particles only in the CHAP group. Bone formation in the CHAP group was more rapid than in the SHAP group until 90days, though no significant differences were observed at 120days. These results suggest that CHAP particles may be useful as a filling material for bone defects in the field of oral and maxillofacial surgery

Clues to Evolution of the SERA Multigene Family in 18 Plasmodium Species

SERA gene sequences were newly determined from 11 primate Plasmodium species including two human parasites, P. ovale and P. malariae, and the evolutionary history of SERA genes was analyzed together with 7 known species. All have one each of Group I to III cysteine-type SERA genes and varying number of Group IV serine-type SERA genes in tandem cluster. Notably, Group IV SERA genes were ascertained in all mammalian parasite lineages; and in two primate parasite lineages gene events such as duplication, truncation, fragmentation and gene loss occurred at high frequency in a manner that mimics the birth-and-death evolution model. Transcription profile of individual SERA genes varied greatly among rodent and monkey parasites. Results support the lineage-specific evolution of the Plasmodium SERA gene family. These findings provide further impetus for studies that could clarify/provide proof-of-concept that duplications of SERA genes were associated with the parasites' expansion of host range and the evolutionary conundrums of multigene families in Plasmodium

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In 1992 the World Health Organization advocated that follicular keratocysts, which may envelop an adjacent unerupted tooth, be classified as an entity different from dentigerous cysts in the classification of odontogenic cysts. However after follicular keratocysts were distinguished from dentigerous cysts, follicular keratocysts have still been erroneously reported as dentigerous cytsts with a keratinizing lining. This reviews Japanese cases of follicular keratocysts, including two cases occurring at the maxilla that have been diagnosed at this hospital

北海道医療大学歯学部附属病院入院患者の臨床統計学的観察

北海道医療大学歯学部付属病院の外来は1978年12月に開始し,入院病棟は1980年6月に24床で開始した.これまでの25年間における病棟入院患者の臨床統計的観察を行ったので報告する.結果は以下に示す.1.総入院患者数は3055例で総歯科新患の10.8%を占めていた.2.口腔外科疾患別では,顎変形症が最も多く393例で入院患者の12.9%を占めていた.3.病床稼働率は17.7%で,平均在院日数は14.2日で経年的に減少傾向にあった.4.25年間の入院診療報酬額は9億5715万円で歯科診療報酬額の20.4%を占めていた.The outpatient division of the Dental School hospital of the Health Sciences University of Hokkaido started in December 1978, and a hospitalization ward started with 24 beds opened in June 1978, and closed in April, 2005. Clinico-statistical observations for 25 the years while the inpatient division, was opened were evaluated. 1. The total number of inpatients was 3055, and comprised 11.8% in all initial patients of the dental hospital for the 25 years. 2. Patients with jaw deformities were the most common, 393 and comprised 12.4% of all hospitalized patients with oral and maxillofacial surgical complaints. 3. The rate of occupiod beds the operating bed ratio was 17.7% and the average length of hospitalization was 14.2 days. This number showed a tendency to decrease over the years. 4. The income from hospitalized care was 957.15 million yen and it comprised 20.4% of the total income of the dental department